Method for treating a fluid by upflow through a bed of adsorbent media

Abstract

Plant (1) intended for the treatment of a fluid (15) by passage of an upflow (90) of said fluid (15) through a bed of adsorbent media particles (13). The plant (1) comprises a reactor (2) intended to contain the bed of adsorbent media particles (13), comprising:a means for injecting and distributing fluid to be treated, disposed at the bottom part, for forming the upflow (90) of fluid (15) within the reactor (2) and enabling the fluidization and expansion of said bed of adsorbent media particles (13);a means for recovering treated fluid;a means for deflecting fluid (20) disposed at the top part, intended for reducing the speed of the upflow (90) of fluid (15) and enabling the formation of a tranquil zone (27), said means for recovering treated fluid being disposed downstream from said tranquil zone (27).

The invention claimed is: 
     
       1. A method of treating a fluid containing pollutant substances by flowing the fluid upwardly through a bed of adsorbent particles having a size of 600-1300 μm, wherein the adsorbent particles are grains or micrograins selected from the group consisting of activated carbon, resin, clay, zeolite, manganese dioxide, iron oxyhydroxide, or a mixture thereof, the method comprising:
 directing the fluid into the bottom of a reactor; 
 from the bottom of the reactor, directing the fluid upwardly through an expansion zone in the reactor and through the bed of adsorbent particles in the reactor; 
 fluidizing and expanding the bed of adsorbent particles in the expansion zone as the fluid flows upwardly through the reactor; 
 directing the fluid upwardly from the expansion zone through a transition zone in the reactor where the concentration of adsorbent particles in the transition zone is less than the concentration of adsorbent particles in the expansion zone; 
 directing the fluid from the transition zone upwardly through a particle deflector disposed in the upper portion of the reactor above the transition zone; 
 as the fluid passes through the particle deflector, the upflowing liquid is deflected and in the process a tranquil zone is created adjacent the particle deflector; 
 as the fluid passes through the particle deflector, at least some of the smaller adsorbent particles come to a stop against the particle deflector and thereafter fall towards the bottom of the reactor; 
 wherein the particle deflector reduces or prevents at least some of the smaller adsorbent particles from leaking past the particle deflector; 
 adsorbing at least some of the pollutant substances in the fluid onto the larger and smaller adsorbent particles as the fluid flows upwardly through the reactor; and 
 directing treated fluid from the reactor and out an outlet disposed above the particle deflector and above the tranquil zone. 
 
     
     
       2. The method of  claim 1  wherein the particle deflector includes a plurality of spaced apart blades that are angled relative to the upward flow of fluid. 
     
     
       3. The method of  claim 2  wherein the blades are acutely angled approximately 60° with respect to the upward flow of the fluid. 
     
     
       4. The method of  claim 1  including maintaining the speed of the upflowing fluid at 20-40 m/h. 
     
     
       5. The method of  claim 1  including maintaining an area in the reactor above the particle deflector substantially free of adsorbent particles. 
     
     
       6. The method of  claim 1  wherein the particle deflector comprises a prism-shaped chute with sides that form an angle α 45°-70° relative to a horizontal reference line. 
     
     
       7. The method of  claim 1  including maintaining the average rate of expansion of the bed of adsorbent particles in the expansion zone from 10%-90%. 
     
     
       8. The method of  claim 1  including extracting adsorbent particles from the reactor and subjecting the extracted adsorbent particles to a solid/liquid separation process that produces a liquid phase and injecting the liquid phase back into the reactor. 
     
     
       9. The method of  claim 1  including:
 taking a sample of the adsorbent particles from the reactor; 
 analyzing the saturation of pollutants adsorbed on the sample of adsorbent particles; and 
 extracting a portion of the adsorbent particles from the reactor when the saturation of pollutants exceeds a threshold value. 
 
     
     
       10. The method of  claim 1  including maintaining the upflow speed of the fluid through the expansion zone at 8-40 m/h. 
     
     
       11. The method of  claim 1  wherein the adsorbent particles are activated carbon particles having a particle size calibrated between 600 and 1300 μm and generally comprising a proportion strictly below 5% of particles of a size smaller than 400 μm.